Protective bandage



United States Patent [72] Inventor Lawrence J. Chamberlain 6856 W. Gunnison, Harwood Heights, Chicago, Illinois 60656 [21] Appl. No. 680,652 [22] Filed Nov. 6, 1967 [45] Patented Sept. 15, 1970 [54] PROTECTIVE BANDAGE 3 Claims, 5 Drawing Figs.

[52] U.S.Cl... 128/154 [51] Int. Cl A6lf 15/00 [50] Field of Search 128/155 157, 149, 153, 154

[56] References Cited UNITED STATES PATENTS 2,599,523 6/1952 Dorr 128/153 2,888,013 5/1959 Levitt 128/153 3,062,210 11/1962 Scholl 128/156 Primary Examiner-L.W. Trapp Attorney- Harbaugh, Thomas and Bruce K. Thomas ABSTRACT: A bandage having a flat, resilient air-permeable, liquid-impermeable membrane with a supporting peripheral flanged edge on one side adapted to adhere to the skin of a patient and provide an enclosure for the wound which is waterproof and allows air to pass to and from the enclosure so that healing is promoted. The membrane of the bandage is constructed of a resilient, foamed plastic material which has interstices that are pervious to air and impervious to liquids. Other embodiments are disclosed including the use of a medicated gauze overlay for the wound which is temporarily held in place within the enclosure of the bandage.

Patented Sept. 15, 1970 3,528,416

I/V VEN 7'01? LAWRENCE J. CHAMBERLAIN I By Mix-" Attorney PROTECTIVE BANDAGE BACKGROUND OF THE INVENTION Most wounds or abrasions of the skin heal best in the presence of air under sanitary conditions including the prevention of the accumulation of moisture or body fluids about the wound. The healing process is aided by immobilization of the member. It is not always possible or practical .to provide the optimum combination of healing conditions for a wound. The use of gauze or absorbent bandages is a compromise which protects the wound for a sufficient time to start the healing process and maintain medicinal compositions thereagainst as a further aid to healing. Cloth bandages become soiled and must be regularly replaced if the healing process extends over any length of time. It is exceedingly difficult and awkward to wash or bathe a member without soiling or wetting the bandage with consequent loss of sanitary conditions for the wound. Although an absorbent pad is often a necessary part of the treatment of a wound, the meansby which it may be afflxed thereto are not always practical, comfortable or convenient.

Various forms of strip bandages having adhesive tabs are available that represent an improvement over the cloth bandage. These bandages are individually wrapped, have non-adhering protective strips on the adhesive layers and have a gauze pad intermediate the ends to cover the wound. Macro perforations are provided in the back side of the strip opposite the gauze pad for the purpose of admitting air. In some forms of bandages the gauze pad is itself encased in a thin plastic sheet having perforations therethrough to allow limited access of air and prevent its adhesion to the wound. All of these forms of unitized bandages are subject to damage and contamination in the presence of water, e.g. during bathing or washing.

The instant invention concerns a form of plastic cover for a wound or for a gauze covered wound which is easily applied, gives permanent protection from moisture and does not prevent the passage of air to and from the enclosed area. The device of this invention does not adhere to dirt, flexes with the movements of the bandaged member and provides an encasement for the wound and medication which is impervious to all contaminants but air. The device of this invention does not have a stiffened crown, hinges or side corrugations to provide both protection and flexibility as in some prior art devices qualifying as wound protectors. The instant invention overcomes these andother drawbacks of the prior art devices.

SUMMARY OF THE INVENTION The instant invention concerns primarily the use of a foamed plastic enclosure, formed in such a manner as to have interstices of small diameter which allow the passage of air but are too small in diameter to allow the passage of liquids. The

enclosure has a depending adhesive edge or flangetherearound, adapted or shaped so as to be positioned over a wound with the edges contiguous to the skin around the wound in a sealed peripheral arrangement. By these means as air enclosure is formed about the wound which prevents the ingress of water, may be used to hold a medicated gauze piece upon the wound and may be subjected to washing without loss of the protective seal.

Accordingly, it becomes a primary object of this invention to provide an enclosing plastic seal for a wound or bandaged area which is characterized by its ability to provide protection from destruction or invasion by liquid media, offer some protection from mechanical shock, and is practical, economical, easy to use, and long lasting. These and other objects of this invention will be described or become apparent as the specification proceeds.

DESCRIPTION OF THE DRAWINGS An embodiment of this invention is shown in the drawings wherein:

FIG. 1 is a top plan view of one form of bandage having a rectangular form;

FIG. 2 is a cross-sectional view taken along lines 2-2 of FIG. 1;

FIG. 3 is a fragmentary view in cross-section of the bandage of this invention applied to a wound and retaining thereon a medicated gauze;

FIG. 4 is a top plan view of another form'of bandage of this invention; and

FIG. 5 is a fragmentary cross-sectional view taken along the lines 5-5 of FIG. 4.

THE PREFERRED EMBODIMENT Referring to the drawings, particularly FIGS. 1 and 2, there is shown a unitzed bandage 10 of a rectangular shape having a peripheral depending flanged edge 12 and a connecting membrane wall or cover 14 therebetween. The outer edge of the flange 12 as indicated at 16 has a pressure sensitive adhesive layer thereon for attachment to the skin around a .wound.

In FIG. 3 the bandage 10 is shown attached around a wound 18 in the skin 20 of a patient and holding within the enclosure 22 a medicated gauze 24 against the wound. In this embodiment the wall 14 is in a flexed position illustrating the ability of the bandage of this invention to flex with the skin and remain attached thereto. Also the bandage may be formed and molded with the cover wall 14 in a somewhat loose configuration whereby it encompasses. a raised position when applied to the skin. The bandage 10 can be lifted at one end to remove or replace the medicated gauze as needed.

In FIG. 4 the bandage 10 is circular and is formed in a flattened configuration for use over a larger wound. FIG. 5 shows the bandage 10 affixed to the skin 20 of a patient to form the enclosure 22 over the wound 18 by meansof the membrane-like cover wall 14'.

Although the drawings are not to scale, they show that the flanged edges 12 are thicker than the wall 14. The relationship of these relative thicknesses is subject to some variation. In general, the wall 14. will be about 0.01 to 0.1 inch in thickness while the flangel2 will be about 0.2 to 0.4 inch in thickness. Also, the height of the bandage represented by the lines A-B in FIG. 2 is subject to variation and may be about 0.2 inch to 0.75 inch or more. With'the higher bandages the thickness of the flange will be about the maximum of the foregoing dimensions;

The bandage .of this invention is formed of a foamed sheet plastic having low waterabsorption properties in which the interstices are concinuous, that is, extend, connect, or communicate between'the enclosure 22 and the outside of the bandage. This interstitial communication can also extend through the side flanges 12. For thispurpose the bandage is formed by molding a foamed plastic composition such as polyvinyl chloride, certain .phenolics, acrylics, celluloses, polystyrene and polyethylene under conditions'to allow rapid expansion under atmospheric pressure. This causes uneven cell structure and a large percentage of interconnecting cells or interstices. Cellular polyethylene exhibits good abrasion,rchemical resistance, flexibility,- toughness, lightness of weight, low moisture absorption, high resistivity in cellular form to be suited for this purpose. Cellular polyethylene is produced by dispersing a chemical blowing agent intimately into the resin and subsequently causing this thermally. sensitive agent 'to liberate gas at a relatively rapid rate to rupture the bubbles formed. This is carried out in an extruder with the application of heat as the material enters the die forming the bandage. By proper adjustment of the heat and pressure the product will have a smooth surface'and an interconnected cell structure as opposed to the usual unicellular structure. Operation of the extruder and mold in the upper range of molding conditions will produce the desired lack of uniformity in bubble size, interconnected ruptured bubbles forming interstices therethrough. These conditions are attained by setting the barrel and head at temperatures of about 300 to 350F. respectively, and measuring the density and porosity of the molded bandage. The barrel and head temperatures are then raised in increments of about 25F until the density of the product is about 0.47 or lower.

Similarly, cellular phenolics having cells which are elongated in the direction of expansion can be formed during the blowing process and the sheets cut across the grain to expose the interstices; A Bakelite foaming resin composition known as BVR18763 having the following formulation of proprietary products can be used:

FOAMIN G RESIN EVE-18763 The components of BVR- 18763 are combined and thoroughly mixed in an agitator-equipped container in order to incorporate air. When the volume has increased about 20 percent in the container, the mixture and the hardener BHR- -l8769 is added in a ratio of about 67 cc. of hardener per pound of BVR-l8763 formulation. Violent agitation is applied for a short time, e.g.l--5 seconds, and the mixture is poured into the mold having the desired volumetric shape to form the flanged bandage of this invention.

Although the term foamed or expanded plastics generally means a resinous material having a completely uniform porous or cellular structure, these materials can be formed with non-uniform porous interconnected interstitial structures by carrying out the foaming processes in a manner to rupture some if not all of the cells into an interconnected form. Such plastics as polyvinyl chloride, polyvinyl acetal,

polyvinyl esters, urea-formaldehyde, melamine-formaldehyde phenol-formaldehyde, polystyrene, cellulose acetate, polyesters and polyurethanes made from polyesters and isocyanates can be used in this manner. Although the chemical resistance of these resins may vary and also their flexibilities, etc., each can be used to form a molded bandage of this invention. A preferred plastic material for this purpose is a proprietary product of the 3M Corporation known as Micro-Pore. Various methods can be used to form the interstices required in the bandage of this invention all of which are applicable to the gas, chemical, aeration, soluble solid, bulk filler and low boiling solvent methods of forming foamed or expanded plastics.

Other proprietary products that can be used are Corfam",

Mille Pore and the vinyl Porvic". A water repellant coating e.g. a silicone, can be applied to those expanded plastics which are not sufficiently water repellant.

Any pressure sensitive adhesive which is adapted for use on surgical bandages and strip bandages can be used for the layer 16. Such products may be based on GR-S type X-40 rubber, GR-S type X-272 rubber, poly-2-ethylbutyl acetate, the copolymerization of 60 parts of n-butyl acrylate and n-hexyl acrylate with 40 parts of methylacrylate, polyvinyl acetate, polyvinyl butyral, stabilized rubber-like polyvinylisobutyl ether (Op panol C) and stabilized high mol. wt. vinyl n-butyl ether polymers. These latter can be compounded with rosin esters, zinc oxide, viscous liquid polyvinylisobutyl ethers (e.g. lgevin 560), with or without a hydrocarbon solvent to form the surgical type pressure, sensitive adhesive layer 16.

A feature of this invention IS the adaptibihty of the bandage to a number of different and convenient uses. The bandage can be formed in various sizes sufficient to cover large wounds or very small cuts. The pad 24 can be a plain sterile gauze adapted to stop the flow of blood or may contain a pain reliever or antiseptic composition. The bandage can be packaged in sterile wax or plastic coated paper packets with separate sterile pads of gauze therein for use as desired. The packet containing the bandages and gauze pads can be properly labelled as to the medicant contained on the pad. The bandages can be conveniently carried on the person or in a purse or luggage and applied anywhere at any time. This eliminates the need for keeping supplies of medicants available for emergency or general use.

Although but one specific embodiment of this invention has been herein shown and described, it will be understood that details of the construction shown may be altered or omitted without departing from the spirit of the invention as defined by the following claims.

Iclaim:

1. A protective bandage consisting of:

a. a unitary flat flexible resilient member formed of expanded plastic as a single molded unit;

b. with an integral depending continuous peripheral flange along one side;

0. said resilient member and said flange having interconnected air permeable and water impermeable interstices therethrough;

d. a layer of pressure sensitive adhesive on the outer edge of said flange; and

e. whereby adherence of said bandage to the skin of a patient by means of said adhesive layer forms a protective flexible enclosure thereupon.

2. A protective bandage in accordance with claim 1 in which said flat resilient member comprises an expanded plastic of the group consisting of polyvinyl chloride, polystyrene and polyethylene formed under conditions that rupture the continuity of bubbles therein to produce a moisture barrier having air transmissive interstices communicating therethrough.

3. A protective bandage in accordance with claim 2 in which said plastic is polyethylene. 

